The functions in the MODEL CHECK menu are used to check the model to meet specific forming simulation criteria. The functions in this menu are illustrated in Figure 5.5.2.
Figure 5.5.2 Model Check
A detailed description of these functions is given in the following sections.
This function allows the user to make consistent normal direction for all elements of the selected part(s).
• Two options are used to select elements: ALL ACTIVE PARTS and CURSOR PICK PART. eta/DYNAFORM will display the normal direction of the selected element.
• An eta/DYNAFORM QUESTION dialog box as illustrated in Figure 5.5.3 is displayed.
Figure 5.5.3 DYNAFORM Question dialog box
Select YES to accept the normal direction of all elements.
Select NO to reverse the normal direction of all elements.
NOTE: The user is recommended to select one part at a time. Parts with branches may not have consistent normal direction.
This function allows the user to check the boundary of displayed part(s). It is used to check the connectivity of elements.
eta/DYNAFORM highlights the free edges along a single surface. For example, if three plate elements share a common edge, the common edge will be displayed as a boundary. An illustration is shown in Figure 5.5.4.
Figure 5.5.4 Surface Boundaries
NOTE: The boundary will remain highlighted until the user hits the CLEAR icon from the ICON bar.
This function allows the user to check the aspect ratio of the displayed plate and solid elements. The aspect ratio is the ratio of the longest side to the shortest side of an element. In eta/DYNAFORM, the default aspect ratio is 8.0. The user may adjust the aspect ratio accordingly.
1. The user may accept the default value of 8.0 or enter any positive real number. eta/DYNAFORM checks the elements with respect to aspect ratio. Elements that exceed the defined aspect ratio are highlighted. The following message will be printed in the message prompt window:
xxx ELEMENTS FAILED CHECK ASPECT RATIO= xxx
or
ALL ELEMENTS PASS CHECK
The number of failed elements and largest aspect ratio will be printed in the message prompt window.
2. An eta/DYNAFORM QUESTION dialog box as illustrated in Figure 5.5.5 is displayed.
Figure 5.5.5 DYNAFORM Question dialog box
Select YES to display the CREATE PART dialog box.
Select NO to skip to the next function.
3. eta/DYNAFORM prints the following message:
SELECT ELEMENT FOR ASPECT RATIO
The user can select any highlighted element to list its aspect ratio in the message prompt window.
This function allows the user to check the minimum values of the interior angles for shell and solid elements. eta/DYNAFORM checks and highlights any elements with interior angles that are less than the defined criteria. The user has an option to adjust the default criteria accordingly.
1. Enter the interior angle in the displayed dialog box (DEFAULT = 1º). If the elements pass the interior angle check, eta/DYNAFORM prints the following message and goes back to the MODEL CHECK menu:
ALL ELEMENTS PASS CHECK!
If some elements do not pass the check, eta/DYNAFORM prints the following message with an option to create a new part.
xxxx ELEMENTS FAILED CHECK
2. At same time, an eta/DYNAFORM QUESTION dialog box as illustrated in Figure 5.5.6 is displayed. If ADD TO NEW PART is selected, the CREATE PART dialog box is displayed to enable generation of new part. If DELETE is selected, all failed elements are deleted. The CANCEL option dismisses the operation.
Figure 5.5.6 DYNAFORM Question dialog box
This function allows the user to check overlapping elements that share two or more edges. If there are overlapping elements, the user can include these elements in a new part.
This function is used to draw a boundary line between elements with opposite normal directions.
If there are no opposing plate normals, eta/DYNAFORM prints the following message in message prompt window:
NORMAL CHECK COMPLETED, NORMAL IS CONSISTENT
This function is used to check the minimum edge length of plate, solid, or beam elements. eta/DYNAFORM highlights all elements which does not pass the user-defined length criteria. The default is 1.0. The user may change the default value.
• If there is any failed element, a dialog box illustrated in Figure 5.5.6 appears. The user can include the failed elements in a new part.
• The user can delete all failed elements.
This function allows the user to check the taper for quadrilateral elements. Taper value is an amount of convergence. A perfect element such as a rectangle has a taper value of zero. The user can enter a value between 0 and 1 in the displayed dialog box (default is 0.5).
• The user can include the failed elements in a new part.
• The user can select any element to list its taper value in the message prompt window.
This function allows the user to check the warpage angle of quadrilateral elements. The user has an option to split the quadrilateral elements into two triangular elements. All elements that fail the defined criteria may be added to a new part.
1. Enter the warpage criteria (default is 5.0º).
2. If elements do not pass the criteria, an eta/DYNAFORM QUESTION dialog box as illustrated in Figure 5.5.7 is displayed.
Figure 5.5.7 DYNAFORM Question dialog box
Select YES to replace warped quadrilaterals element with triangular elements.
Select NO to reject the operation.
3. If the warped elements are not replaced, eta/DYNAFORM will ask the user to include the failed elements in the new part or continue to the next step.
4. The user can select any element to list its warpage angle in the message prompt window.
This function allows the user to check the angle between plate elements normal with user defined angle. Feature line is the edge of two adjacent plate elements with the angle between the plate normal equal or greater than the angle criteria.
1. Enter angle criteria (default is 20º).
2. Any feature line where the angle between the normal of adjacent elements is larger or equal to the angle criteria will be highlighted. eta/DYNAFORM provides options for user to generate the plotel elements.
3. If YES is selected, eta/DYNAFORM provides options for user to keep the element in a new part. The user creates new part using the CREATE PART dialog box.
This function is used to check if the die surface has any back draft wall angle. The program checks for an undercut of the elements of the die surface based on default angle criteria. The user is given an option to keep the failed elements in a new part.
This function will display 10 blank elements that have the minimum time step, i.e., the 10 smallest blank elements. Both the time step and element ID number are printed in the message prompt window.
There are several functions provided in the SECTION CUT dialog box as described in Section 5.1.7 .
This function allows the user to measure the deviation between surface and element. The dialog box is illustrated in Figure 5.5.8.
Figure 5.5.8 Surface Deviation dialog box
• SURFACE AND MESH
Check the deviation between surface and mesh. If this option is selected, the two option buttons below are corresponding to Select Surfaces and Select Elements.
• MESH AND MESH
Check the deviation between element and element. If this option is selected, the two option buttons below are corresponding to Select Elements and Select Elements.
• REFERENCE BY SURFACE
Compare deviation with reference by surface. This option is only available for surface and element check.
The user can select the surface and element to be measured and then define DEVIATION RANGE. Finally, click on PLOT to display the deviation plot, as shown in Figure 5.5.9. When the range is set to 0, the deviation range will be adjusted automatically according to the practical deviation. The user can also click on SHOW VALUE button and then display the deviation value by clicking nodes with cursor, as shown in Figure 5.5.10. Click the right button to reject the selection.
Figure 5.5.9 Deviation Plot
Figure 5.5.10 Display Deviation Value
This function is used to check the interference of elements between different layers. The penetrated elements will be highlighted. The dialog box is illustrated in Figure 5.5.11.
Figure 5.5.11 Interference Check
• AMONG PARTS
Check interference between two arbitrary parts. The user may select multiple parts.
• BY PART GROUPS
Check interference between two part groups. Toggle on this option to select master part group and slave part group. The program will check the interference between two groups. Parts in groups do not have interference check.
• CHECK TOLERANCE
This function is used to control calculation precision. The default value is 0.01. After completion of definition, click CHECK.